A woodcut depicts three floral ornaments arranged horizontally at the top center of the page.

de radiis solaribus on solar rays, and de coloribus per artem fiendis on colors made by art.

2. De secretis naturae et artis operibus, et de nullitate magiae On the Secret Works of Art and Nature, and on the Nullity of Magic. This work also has the title de mirabili potestate artis et naturae on the wonderful power of art and nature, and various treatises have likewise been made from the eleven chapters of which it consists.

3. De speculis On Mirrors, is located behind the treatise de perspectiva on perspective in an edition that I will indicate below.

4. De alchemia On Alchemy, or Speculum alchemiae Mirror of Alchemy.

5. De retardandis senectutis accidentibus On Retarding the Accidents of Old Age, has likewise been made into three different treatises because of its divisions. Bacon had sent it to Pope Nicolaus IV in order to gain his favor.

Editions.

Fratris Rogeri Bacon, ordinis minorum, Opus maius ad Clementem quartum pontificem Romanum. Ex MS. codice Dublinienſi, cum aliis quibusdam collato, nunc primum edidit S. Jebb, M. D. Londini, typ. Gul. Bowyer, 1733. Fol. Brother Roger Bacon, of the Order of Friars Minor, Greater Work for Pope Clement IV. From the Dublin manuscript codex, compared with certain others, now first edited by S. Jebb, M.D. London, printed by William Bowyer, 1733. Folio.

Since the printing of this work, one has truly come to know Bacon.

Perspectiva, in qua quae ab aliis fuse traduntur, succincte, nervose et ita pertractantur, ut omnium intellectui facile pateant. Nunc primum in lucem edita opera et studio Iohannis Combachii, Francof. typ. Wolfg. Richteri, sumt. Ant. Hummii, 1614. 4. Perspective, in which those things which are dealt with at length by others are treated succinctly, vigorously, and in such a way that they are easily accessible to the intellect of all. Now first published to the world by the work and study of Johannes Combach, Frankfurt, printed by Wolfgang Richter, at the expense of Anton Humme, 1614. Quarto.